Rice is one of the most widely consumed staple cereal food in the world. 89 % of the diet of Asians constitutes rice; while 45 % of those who have their origin in the Western countries have wheat as their major source of diet, rest consuming rice as major source of food1. However, with increasing population and rising economical constraints with widening margin between the rich and the poor, especially in the Asian regions, the per capita consumption of rice is predicted to increase remarkably. This may in turn reflect on rice economy in those countries trying to become self-sufficient in rice production. But what makes rice a major crop of the world and as a preferred staple food for many?

1. Nutritional value:

FAO figures indicate that rice supplies 698 calories per day; wheat 267 calories per day; maize 208 calories per day; millet and sorghum combined 145 calories per day.

Even though the chemical composition of rice varies with the genotype, the conditions under which that they have been grown, their genetic factor and other environmental factor such as location and season of cultivation, fertilizer treatment, degree of milling, and conditions of storage also influences the nutritional status of the crop and its yield.

In general rice grain contains: 80 % starch, 7.5 % protein, 0.5 % ash, and 12 % water. The starch in rice is a mixture of amylase and amylopectin, and the proportion of these two determines the cooking and eating qualities of the rice. However, the carbohydrate status of the food does not affect the nutritional quality of the rice. In spite of the fact that rice is a primary source of carbohydrate, is also the main source of protein. The main problem for rice eating population is with children for whom the protein requirements are very high and their stomach is too small to hold enough intake of rice, for it does not suffice their calorie requirements. In such instances, wheat is a good alternative, or supplement rice with a legume diet. However, the point to be noted at this juncture is that, even though the protein content is quite small in rice the quality of protein found in rice is superior to wheat, maize or sorghum.

For example, lysine, the most important limiting essential amino acid constitutes 4 per cent of rice protein, which is twice the amount of that found in flour or hulled maize. Two other essential amino acids, threonine and methionine are higher in rice protein than in wheat, maize or sorghum. However, the quantity of these amino acids is less than the required daily intake and so has to be supplemented with an additional grain legume, fish or meat in their diet. Like all other cereals rice do lack vitamin A, D and C. Nevertheless, small amounts of niacin, riboflavin and threonine are found in brown rice than in unpolished rice, as the B-complex vitamins are concentrated largely in the bran and germ. Home-pounded rice and par boiled rice are usually found to contain large amount of these vitamins than polished rice. This is the reason why nutritionists recommend eating brown rice. However, there is a “cultural stigma” on the economical status in consumption of brown rice, as brown rice is packaged before the polishing stage and, hence does not take into account the cost of polishing; and so the overall cost is less, and the cooking quality of the rice is reduced.

2. Negatives can also be positives:

Nevertheless, poor nutritional resources in rice as a staple food, like low in protein, minerals, and vitamins, in fact contributes advantageously for placing rice as a main food, for many in the world is the readiness of the carbohydrates to be digested with ease, and that in turn improve its protein utilization efficiency – 63 for rice, compared with 49 for wheat and 36 for maize1. Above all, rice is relatively non-allergenic, which means cases of hypersensitivity reaction to this cereal food are rare. This is the main reason for rice being prescribed as not only the main source of diet for hypersensitive patients, but also as the first source of diagnostic staple diet sans other ingredients, followed by adding other sources one by one, until the source of allergen is identified. Moreover, the low sodium content in rice allows rice to be recommended as a good diet for patients suffering from hypertension. Overall, the acceptability of rice as a food has increased the demand by all countries to become self-sufficient. Consequently, rice has foreseeable future, and in fact all rice-producers are unrelentingly looking forward to increase the yield and the total production of rice.

3. Agricultural Produce:

From the peasant’s frame of mind for world-wide cultivation in various soil types and terrain using irrigation and monsoon-dependent agriculture, rice is the only available semi-aquatic cereal crop. In other words, rice is the only crop that thrives and survives under standing water, while majority of the world’s most important world crops like cassava, wheat, sorghum, yam, white potatoes, and sweet potatoes all dies. Rice is the only crop that can be grown year after year in standing water without any problems. In addition, the increased silicon content in rice hulls, to a lesser degree in their leaves and stems, enhances its resistance to insect and pathogen attack, which is a common problem frequently encountered under waterlogged conditions. Above all, rice also grows in a wide arrange of soil conditions ranging from acidic to alkaline conditions, the fact being that the pH of the soil gets neutralized to acceptable levels under waterlogged conditions.